Technical Field
This application relates in general to providing security in mobile electronic devices and in particular to techniques that verify authorized users via touch sensors.
Background Information
For some time it has been common to provide mobile devices such as smartphones, tablet computers, laptop computers and the like with various mechanisms to provide lock-unlock functions. These functions help limit use of the device, to prevent unwanted persons from gaining access. In general a mobile device will perform a lock function when a lock activation mode has been selected by an authorized user. In addition to activation at power on, a mobile device will typically also activate the lock function when there is no input from a user for a period of time.
Commonly known factors for controlling lock-unlock are the entry of passwords via a keyboard, finger swipe motions or drawing gestures on a touchscreen, sensors to detect fingerprints, facial recognition via built-in cameras, and others. It is also known to provide further security by combining two or more such factors before granting access to the device.